While the toll rose from 53 to 73 in Sikkim, West Bengal has reported 15 deaths, nine in Bihar, 11 in Nepal, seven in Tibet and one in Bhutan.

Twenty more bodies were recovered in quake-hit Sikkim taking the toll in Sunday's powerful 6.8 magnitude temblor to 116, which may go up further with rescue teams still to reach about 15 more affected remote villages.

While the toll rose from 53 to 73 in Sikkim, West Bengal has reported 15 deaths, nine in Bihar, 11 in Nepal, seven in Tibet and one in Bhutan.

Officials said rescue teams found six bodies in East Sikkim and 14 in North as they managed to enter Dzongu from Mangan, the headquarters of North Sikkim where the strong quake was epicentred.

There is still no trace of 120 residents of Bay village in North Sikkim, located between Lachung and Chungthang, three days after the quake.

"We find no trace as yet of 120 people living in 14 huts at Bay village as the area is totally devastated. There is a lot of debris... and the residents have gone missing," National Disaster Response Force team in-charge Nisith Upadhyay told PTI.

"We are afraid some bodies may have been trapped under the flattened houses as boulders are lying strewn all over," he added.

40 foreign tourists stranded in North Sikkim were evacuated, a Union home ministry official said.

Defence forces and other agencies struggled hard to clear mud, rocks and boulders blocking roads to reach the affected areas.

In Lalchung, a seriously injured bus passenger was rescued in an army helicopter in a daring operation as there was no place to land.

Two brigadiers jumped down nearly seven to 10 feet from the chopper to make space for the passenger who was helped into the hovering aircraft.